/*
 * Copyright � 2002-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System.Net;
using System.ComponentModel;
using System.Globalization;
using System.Text.RegularExpressions;

namespace Spring.Core.TypeConversion;

/// <summary>
/// Converts string representation of a credential for Web client authentication
/// into an instance of <see cref="System.Net.NetworkCredential"/>.
/// </summary>
/// <example>
/// <p>
/// Find below some examples of the XML formatted strings that this
/// converter will sucessfully convert.
/// </p>
/// <code escaped="true">
/// <property name="credentials" value="Spring\bbaia:sprnet"/>
/// </code>
/// <code escaped="true">
/// <property name="credentials" value="bbaia:sprnet"/>
/// </code>
/// </example>
/// <author>Bruno Baia</author>
public class CredentialConverter : TypeConverter
{
    private readonly static Regex credentialRegex = new Regex(
        @"(((?<domain>[\w_.]+)\\)?)(?<userName>([\w_.]+))((:(?<password>([\w_.]+)))?)",
        RegexOptions.Compiled);

    /// <summary>
    /// Can we convert from the sourcetype
    /// to a <see cref="System.Net.NetworkCredential"/> instance ?
    /// </summary>
    /// <remarks>
    /// <p>
    /// Currently only supports conversion from a <see cref="System.String"/> instance.
    /// </p>
    /// </remarks>
    /// <param name="context">
    /// A <see cref="System.ComponentModel.ITypeDescriptorContext"/>
    /// that provides a format context.
    /// </param>
    /// <param name="sourceType">
    /// A <see cref="System.Type"/> that represents the
    /// <see cref="System.Type"/> you want to convert from.
    /// </param>
    /// <returns><see langword="true"/> if the conversion is possible.</returns>
    public override bool CanConvertFrom(
        ITypeDescriptorContext context, Type sourceType)
    {
        return (sourceType == typeof(string));
    }

    /// <summary>
    /// Convert from a <see cref="System.String"/> value to an
    /// <see cref="System.Net.NetworkCredential"/> instance.
    /// </summary>
    /// <param name="context">
    /// A <see cref="System.ComponentModel.ITypeDescriptorContext"/>
    /// that provides a format context.
    /// </param>
    /// <param name="culture">
    /// The <see cref="System.Globalization.CultureInfo"/> to use
    /// as the current culture.
    /// </param>
    /// <param name="value">
    /// The value that is to be converted.
    /// </param>
    /// <returns>
    /// A <see cref="System.Net.NetworkCredential"/> instance if successful.
    /// </returns>
    public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
    {
        if (value is string)
        {
            string credentials = (string) value;
            Match m = credentialRegex.Match(credentials);

            if (!m.Success || m.Value != credentials)
            {
                throw new ArgumentException(String.Format("The credential '{0}' is not well-formed.", value));
            }

            // Get domain
            string domain = m.Groups["domain"].Value;

            // Get user name
            string userName = m.Groups["userName"].Value;

            // Get password
            string password = m.Groups["password"].Value;

            return new NetworkCredential(userName, password, domain);
        }

        return base.ConvertFrom(context, culture, value);
    }
}
